Cement grout mixing and distributing machine



March 2, 1937. e. w. GRAYSON.

CEMENT GROUT MIXING AND DISTRIBUTING MACHINE Filed Jan. 6, 954

3 Sheets-Sheet 2 G. w. GRAYSQN Filed Jan; 6, 1934 CEMENT GROUT MIXINGAND DISTRIBUTING MACHINE March 2, 1937. I

March 2, 1937. G. w. GRAYSON 2,072,301

' CEMENT GRdOT MIXING AND DISTRIBUTING MACHINE Filed Jan. 6, 1954 3Sheets-Sheet 3 Patented Mar. 2, 1937 PATENT OFFICE CEMENT GROUT MIXINGAND DISTRIBUT- ING MACHINE George Wentworth Grayson, Darling Point, nearSydney, Australia, assignor ,to John Thomas McKee, Sydney, AustraliaApplication January 6,

1934, Serial No. 705,489

In Australia January 16, 1933 2 Claims.

This invention relates to-cement grout mixing machines of the typedesigned to supply a cement and sandandwater mix having devices to Ienable the maintenance of the sand content of the grout at apredetermined ratio irrespective of any moisture created variation ofthe sand volume and having devices to prevent segregation of the; groutconstituents while being conveyed from grout mixing apparatus to thepoint of application.

A machine of the type referred to consisted of a proportioning millhaving a separate hopper forsandand cement each having a gravitydischarge, having revolvable vanes in the orifice of said discharge andhaving a shutter slidable on said vanes; a mixing trough juxtaposedimmediately below theproportioning mill, having on a rotatable shafttherein a multiplicityof mixing and conveying paddles and having agravity discharge, and having a water pipe; with delivery nozzlesjuxtaposed, above saidmixing paddles; an agitating and distributingtrough having swivel connection to said mixing trough discharge andhaving a rotatable shaft therein and. having amultiplicity of helicallyarranged agitating and conveying paddles on said shaft; mechanism beingprovided to rotate said vanes and the mixing and conveying devices. V

In such machines used heretofore it. has been necessary to rely upon anoperator to make periodic tests of the grout mix and by instrumentsinvolving some knowledge of mathematics to vary the. allocation of oneor other of the grout constituents to maintain the correct proportioningthereof. Suchmachines have proved more or less satisfactory in practicehaving overcome prejudice to the use of a cement grout founded onprevious failures of it (occasioned generally by incorrect proportioningof cement and sand due to the moisture created changesin the weight perunit volume .of the sand, faulty mixing, absence of time control of.mixing and segregation of the: mix) and have established the use of.cement grout in road construction and in the ballasting of trainper-ways and encouraged inquiries as. to. the use of. cement grout inother fi'eldsof industry, as for example, in canal and irrigation,channels, and retaining walls and like concrete, work. Experience hasproved. however that, operators cannot be rel'ied'upon to adjust themachine .to continuously correctly allocate the grout constituents, forthe sand volume in the different supplies to the machine is constantlyaltering. and, tests .of the concrete produced by such machines hav sh wS bstantial variations in crushing'str'esses due entirely to mishandlingof the machines. Further the distributing troughs in machinesheretoforehave not been'as efiective as is desirable, owing to pebbles and thelike jamming between the conveyer and the trough, resulting in stoppageof the machine with consequent dislocation of work and. spilling 'of thegrout.

Now this invention has been especially devised to provide a cement groutmixing machine which will at all times automatically produce a cementgrout having a predetermined sand content irrespective of any moisturecontent or voids in the sand orbulking thereof, and it has been furtherdevised to providea combined mixer and distributor wherein the cement isretained until it changes to a gelatinous condition and wherein the sandparticles and/or other grout constituents are efiectively coated withthe cement,'conveyors liable to blockageibeing eliminated.

The previous machine made use of the known physical property of sandnamely:-

that although a given quantity of sand containing the usual moisturecontent occupies a greater volume than the same quantity when dry andrammed, when completely inundated it resumes its dry loose volume;

- but only to test the composition of the grout subsequent to the mixingthereof. In this present invention this same property of the sand .isutilized prior to the mixing of the grout to assure a precisepredetermined compo'sitionbf grout which remains invariable irrespectiveof weather conditions.

The principal characteristics of the improved cement grout mixingmachine are devices to inundate sand in combinationwith mechanism tomeasure inundated sand and to measure cement and a rotatablefrusto-conical mixing and distributing drum having an inlet at one endand a discharge at the other end, with mechanismv to vary theinclination of said drum and to enable it torbe swivelled laterally.

. But in order that this invention may be readily understood and carriedinto practical effect it will be described with reference to thedrawings accompanying and forming part of this complete specification.Fig. 1 is a longitudinal elevation and Fig. 2 is a plan of the generalarrangement of the machine. Fig. 31s a longitudinal elevation. Fig. 4 isa plan of the machine incorporating certain modifications.

Referring to Figs. 1 and 2 the machine is con- .Stituted of a wheeledchassis I with or without ordinary steering and propelling mechanism.Mounted on the chassis 1 is a sand bin or boot 8 and acement bin or boot9. Casings l9 and H extend from the boots 8 and 9 to a discharge hopperl2 and contained within said casings are endless bucket elevators l3 forsand and [4 for cement, erected and adjusted as well understood.

The elevators l3 and 54 are for the purpose of proportioning thequantities of the sand and cement and to raise these materials anddeliver them to the discharge hopper l2. They are of the usual buckettype and each is driven independently from sprockets l5 and i6 on thecounter shaft [1. The sprocket I5 drives the sand elevator l3 throughsprocket l8 and the sprocket l6 drives the cement elevator l4 throughthe sprocket H3. The sprockets I8 and I9 are driven from a prime motorby an ordinary gear train. The sprocket l9 may be changed to vary theamount of cement delivered by the elevator l4 according to the sand tocement proportions required or alternatively the number or the size ofthe buckets may be varied to achieve the same purpose.

A pump 20 is provided to deliver water to the boot 8 through pipes 20Ato inundate sand therein. This water after inundating the sand becomesthe mixing water for the cement grout. Almost all this water (which willapproximately equal the volume of voids in the sand) will be lifted bythe sand elevator buckets l3 and discharged with the sand into thehopper l2. Excess inundation water will overflow the boot 8 into pipe 2|which is a suction pipe for a pump 22 delivering through pipe 23 intothe discharge end of the hopper l2 to be used if required in the mixingof the grout.

The discharge hopper I2 delivers by gravity flow the sand, cement andwater to a swivel hopper 24 which in turn deposits it in a mixing feeder25 wherein a helical conveyor mixes the ingredients and delivers theminto a mixing and distributing drum 21. The swivel hopper 24 issupported from the pivot 28 which in turn is fixed to the inner circle29 of a turntable 30 supported by the members 3| and 32 fastened to thestandards 33. The conveyor 26 is driven by shaft 34 which is aflixed tothe mixing drum 21 by a spider indicated at 35 and is rotated with saiddrum 21. The mixing and distributing drum 21 is a hollow frustum of acone its small end being about one-third the diameter of its large endand it is of sufficient length to give the correct periods of wettingand mixing of the ingredients as well as provide reach for distributingthe grout. The drum has its axis lying at such an angle that its bottomis approximately horizontal to prevent natural gravity flow towards thedischarge end thereof. Attached to the inner wall of the drum are one ormore longitudinal vanes 26A provided to lift (assisted by thecentrifugal force engendered by the rotation of the drum) the groutmaterials in the drum as it is rotated and to cause them to drop onreaching the top centre of rotation. Owing to the inclination of thedrums axis the dropping ingredients are advanced along the drum anamount corresponding to the tangent of the angle of inclinationmultiplied by the diameter. The rotation of the drum causes the materialtherein to roll and this action combined with the compulsory dropprovides a thorough mixing of the ingredients. The drum may also have aplurality of annuli placed at equal distances therealong to constituterearders to the free flowing of the grout The drum 21 is rotated at asuitable speed but the peripheral speed must not be such that thecentrifugal force imparted to the grout will exceed the weight of it.The rotation is effected by gearing 31 and 38, universal rod 39, gears40, M and sprockets 42, 43 driven through a clutch (not shown) by shaft45 from bevel gear 46, which in turn is driven by pulley 41 from enginepulley 48 through belt drive 49. This mixing and distributing drum 21 issupported on rollers 52 in cage 53 which in turn is supported bybalancing springs 54 attached to hook 55 on the standard 58. The cage 53is rigidly mounted in a cradle which can swivel about the vertical axisof the swivelling hopper 24.

The framework 56 of the cradle is fixed at one end to the swivel hopper24 and at its other end has an adjustable suspension rod 51 anchored tohook 55 and provided with a hand wheel 59 to enable adjustment of theinclination of the drum 21. A removable standard 60 is provided tosupport the drum 21 when not in use.

The grout discharge hopper 6|, which receives the grout from the drum21, is attached to the framework 56 and delivers the grout through thethroat 62 into the distributing chute 63. This distributing chute 63tips at will of the operator on the pivot 64 and can be swung laterallyon the swivel 65 the whole being supported from the discharge throat 62.The distributing chute 63 is balanced by Weight 58.

It will be seen that the anchorage 55 for the suspension rod 51 and thebalancing springs 54 are vertically above one another and therefore havethe same axis of rotation as the swivel hopper 24 and the drum 21.

In the modified construction depicted in Figs. 3 and 4 the separate sandand cement boots 8 and 9 and the elevators l3 and I4 therefor withoperating mechanism and the mixing feeder 25 are dispensed with.

In place of the noted integers is a measuring receptacle 66 of uniformcross section, (for example square) having above the measuring portion ahopper mouth 61 (to facilitate the filling and discharge) and in saidreceptacle is a scale 68. Trolley wheels 69 have axles fixed to the backwall of the receptacle 66 andrguides provided on the chassis. Hoistingcables 1| anchored to the receptacle 66 are reeved through pulleys 12 onstandards 13 and pass to winding drums 14 operated by an ordinary trainof gears from the prime motor, clutches and brakes being provided aswell understood. Operation of the hoisting gear lifts the measuringreceptacle 66 and tips it as indicated at 15.

Juxtaposed the tipping position of the receptacle 66 is a mixing mill 16having on a spider 11 on a rotating spindle 18 a multiplicity of vanes19 set at angles of approximately 30 off the horizontal and said vanes19 may have orifices therein to assist thorough intermingling of groutconstituents, and some of them are set at opposite angles also to createturbulence in stirring. The spindle 18 is rotated by gearing from theprime motor as well understood. A valve 88 in the bottom of the mill isoperated by lever 8| to open a discharge to a second mill 82 havingsimilar agitating mechanism to that described for mill 16, but itsdischarge valve 83 is adapted to be set by hand wheel 84 to regulate thedischarge therefrom which passes to the swivel hopper 24 beforedescribed.

The delivery of the grout ingredients to the mixing and distributingdrum 26 by the mechanism illustrated in Figs. 1 and 2 has been describedwith reference to the respective integers of the machine. In themechanism illustrated in Figs. 3 and 4, and assuming for example themaking of a grout in the proportions of one cement to two and one halfsand, (two cubic feet cement to 5 cubic feet sand will require about 13%gallons of water) the receptacle 66 is first charged with the inundationwater up to approximately 2% cubic feet mark on the scale 68. Thereceptacle is next charged with sand up to the 5 cubic feet mark, afterwhich it is charged with cement up tothe '7 cubic feet mark. 'Theinundator receptacle is now charged and is ready to be lifted by thecables H and tipped into the mixing mill 86 where the ingredients areagitated and stirred by the vanes 19 for at least one and a half minutesto enable the cement to reach a gelatinous state. After thisperiod ofmixing, the valve 80 is operated by the lever 8| and the grout isdischarged into the second agitating mill 82 from whence it flowscontinuously (by adjustment of the hand wheel 84) and at the same timeagitated to the swivel hopper 24 and then into the revolvingdistributing drum 21. The receptacle 66 can be operated sufficientlyfast to normally keep the mill 82 charged.

In the mixing and distributing drum 2'! the vertical inclination of itsaxis determines the grout consistency, which is important. It isnecessarily determined by experiment with the particular cement and sandto be used and is fixed by turning the screw hand wheel 59. After theinclination has been determined, the spirit level 86 is adjusted tohorizontal by altering the capstan screws 81, and the machine is thenready to work. When the machine is standing on uneven ground, the angleof inclination will change as the mixing drum 21 is traversed laterally(it can be swung through a horizontal angle of approximately 180); ifcorrection of this irregularity of inclination is not cared for,variations in the volume and consistency of the grout will result. Tocontrol this grout consistency, the operator watches the lever 86, whilemanipulating the flushing chute 63 with the operating handle 88. As thebubble in the level 86 moves, the hand wheel 59 is turned in thedirection necessary to bring the bubble back to its central position.

I claim:

1. In a cement grout mixing and distributing machine, a frame, a movablymounted bearing, an adjustable support for the bearing pivotallyconnected to the frame, a rotatably mounted frusto conical mixing anddistributing drum having an inlet opening at its larger end and adischarge opening at the smaller end journaled in said bearing,adjustable guy rods connecting the discharge end of the drum andpivotally secured to the frame coaxially with the support for thebearing, means for elevating and lowering the discharge end of thedistributing drum, and means for moving the drum horizontally about theinlet end thereof. 7

2. In a cement grout mixing and distributing machine, a frame, a movablymounted bearing, a support for the bearing'pivotally connected to theframe, a hopper pivotally mounted on the frame for movement about avertical axis, a rotatably mounted frusto-conical mixing anddistributing drum having an inlet opening at the larger endcommunicating with the pivotally mounted hopper and a discharge openingat the smaller end, the drum being journaled in the said bearing,adjustable guy rods connecting the discharge end of the hopper andpivotally secured to the frame coaxially with the support for thebearing, means for elevating and lowering the discharge end of the drum,and means for moving the drum horizontally about the pivotal axis of thehopper.

GEORGE WEN'IWORTH GRAYSON.

